Marine Weather Net

Straits of Florida from west end of Seven Mile Bridge to south of Halfmoon Shoal out 20 to 60 NM Marine Forecast


OVERNIGHT

S
WINDS
5 - 10
KNOTS

WEDNESDAY

VARIABLE
WINDS
5 KNOTS

WEDNESDAY NIGHT

ESE
WINDS
5 - 10
KNOTS

THURSDAY

E
WINDS
5 - 10
KNOTS

The Marine Weather Forecast In Detail:
GMZ074 Forecast Issued: 1030 PM EDT Tue Jul 27 2021

Overnight...South Winds 5 To 10 Knots, Becoming Southeast To South. Seas Around 1 Foot. Isolated Showers And Thunderstorms.
Wednesday...Variable Winds Near 5 Knots. Seas Around 1 Foot. Isolated Showers And Thunderstorms.
Wednesday Night...East To Southeast Winds 5 To 10 Knots. Seas Around 1 Foot. Isolated Showers And Thunderstorms.
Thursday...Mainly East Winds 5 To 10 Knots. Seas 1 To 2 Feet. Isolated Showers And Thunderstorms.
Thursday Night...East To Southeast Winds Increasing To 10 To 15 Knots. Seas Building To Around 2 Feet. Isolated Showers And Thunderstorms.
Friday...East To Southeast Winds Near 10 Knots, Decreasing To 5 To 10 Knots. Seas Subsiding To 1 To 2 Feet. Isolated Showers And Thunderstorms.
Friday Night...East To Southeast Winds Near 10 Knots. Seas 1 To 2 Feet. Isolated Showers And Thunderstorms.
Saturday...East To Southeast Winds 5 To 10 Knots. Seas Subsiding To Around 1 Foot. Isolated Showers And Thunderstorms.
Saturday Night And Sunday...East To Southeast Winds 5 To 10 Knots. Seas Around 1 Foot. Isolated Showers And Thunderstorms.
Sunday Night...East To Southeast Winds Increasing To Near 10 Knots. Seas Building To 1 To 2 Feet. Isolated Showers And Thunderstorms.
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Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas: GMZ005
1030 PM EDT Tue Jul 27 2021

A ridge axis will straddle Florida over the next several days. Light to gentle southeast breezes, and near normal rain and thunder chances are expected. A meager wind surge Thursday night may result in a brief period of moderate breezes for portions of the Straits of Florida and near the Reef, however, light to gentle breezes will prevail through the extended forecast.

Gulf Stream
The Approximate Shoreward Edge of the Gulf Stream as of July 27...
- 57 NM South of Dry Tortugas Light...on Loggerhead Key.
- 24 NM South of Cosgrove Shoal Light...off the Marquesas Keys.
- 21 NM South of Sand Key Light...off Key West.
- 21 NM South of Looe Key...off Big Pine Key.
- 21 NM South of Sombrero Key Light...off Marathon.
- 13 NM Southeast of Alligator Reef Light...off Islamorada.
- 6 NM Southeast of Molasses Reef Light...off Key Largo.
- 3 NM East of Carysfort Reef Light...off Ocean Reef.
Area Forecast Discussion
National Weather Service Key West FL
958pm EDT Tuesday July 27 2021

A very warm and humid late July evening is underway across the Florida Keys, with current air temperatures in the mid 80s and dewpoint temperatures in the mid 70s. Skies are mostly clear except over portions of Florida Bay and the shallow Gulf waters adjacent to Cape Sable, where a few showers and thunderstorms are ongoing, having initiated along a few colliding, intersecting, and merging mesoscale convergence zones. Winds are rather light and variable across the service area, less than five knots at all reporting stations. Data from the Key West evening radiosonde balloon indicated a moderately unstable thermodynamic stratification with some substantial low-level convective inhibition energy. Although the near-surface air mass was rich in moisture, the moist layer was rather shallow, with dewpoint depressions 6-10C through the 925-700mb layer. A large-scale composite analysis revealed a huge, deep layer mean anticyclone centered over the middle of North America, with a smaller circulation north of the Greater Antilles. The Florida Keys and adjacent coastal waters were located beneath a region of nondescript flow, with little forcing for large-scale ascent.

The content of current forecasts, prepared by the day shift, is consistent with our evening diagnosis and threat assessments. Therefore, we anticipate no substantive change to either the local digital forecast or the derived products.

Marine
No watches, warnings, or advisories are in effect for any Florida Keys coastal waters zones. A ridge axis will straddle Florida over the next several days. Light to gentle southeast breezes, and near normal rain and thunder chances are expected. A meager wind surge Thursday night may result in a brief period of moderate breezes for portions of the Straits of Florida and near the Reef, however, light to gentle breezes will prevail through the extended forecast.

Climate
On this day in 1930, the daily record low temperature of 70F was recorded in Key West. Temperature records date back to 1872.

NOAA Key West FL Office: Watches - Warnings - Advisories
FL...None. GM...None.